Checked vs unchecked exceptions

Checked	Unchecked
Compiler requires catching or declaring them	No compile-time catch/declare requirement
Subclasses of Exception excluding RuntimeException	RuntimeException and its subclasses
Example: IOException, SQLException	Example: NullPointerException, ArithmeticException

import java.io.IOException;
class Example {
    static void read() throws IOException {
        throw new IOException("Read failed");
    }
    public static void main(String[] args) {
        try { read(); }
        catch (IOException e) { System.err.println(e.getMessage()); }
    }
}

Catch exceptions when recovery is possible, or declare checked exceptions with throws. Prevent unchecked exceptions through validation and correct program logic; do not catch Exception indiscriminately.